The present invention relates to a xenon lamp for a vehicle such as an automobile, truck, bus, van or tractor for forward lighting applications. More particularly, the xenon lamp provides (1) for a reduction in the dimensions of the vehicle or automotive reflector housing such a lamp, (2) an improvement in the divergence of the light beam serving the automotive applications, and (3) both the low beam and high beam illumination needs of the vehicle.
Automotive designers are concerned in lowering the hood lines of cars in order to improve their appearance and aerodynamic performance. One of the primary factors that must be taken into account in such lowering is the required dimensions of the automotive headlamps. For example, the automotive headlamp has a requirement of providing substantially instantaneous light which is typically yielded by one or more tungsten incandescent filaments housed within automotive headlamps to provide for low and high beam illuminations. The one or more incandescent filaments must be comprised of at least certain dimensions such as the amount, length and wire size of tungsten in order to provide for the illumination needs of the automobile. These filament dimensions essentially define the light source of the headlamp which, in turn, determine the dimensions of the related reflector of the headlamp such as the reflector's size and shape in order to provide desired beam patterns at sufficient levels to serve the illumination needs of the headlamp. The size and shape of the reflector are limiting factors in lowering the hood line of cars.
It is desired that a light source for automotive headlamp other than an incandescent filament be provided such as a discharge type lamp not having a filament so that the dimensions of a related reflector may be reduced in order to allow the automotive designers to further pursue the lowering of the hood line of the automobile. It is further desired that the discharge light source provide for the instantaneous light for the automobile and also that a single such light source provide for both the low and high beam illumination needs of the automobile. Still further, in addition to the discharge light source serving the needs of automobile, it is desired that the instantaneous light source find lighting applications in the home, office and other commercial and industrial usages.
Accordingly, it is an object of the present invention to provide a discharge light source for lighting applications and which is particularly suited for automotive applications that provides for instantaneous light and for a reduction in the overall dimensions of the related reflector of an automotive headlamp.
It is a further object of the present invention to provide a single discharge lamp that acts as a light source to provide both the low and high beam illumination needs of the automobile.